Electric heater.



MIN BELIN MUGERRY. 111150111110 HEATER.

AIPLIOATIGN FILED HABA, 190B.

950,599. Paf-11111911 mar. 1,1910.

Wee 6 @wf/$7 g/VM .gy

7 @man UNITED STATES OFFICE.

MlN BELIN MQGEBBY, QF GRAND RAEID-S, MICHIGAN, SSIGNGR TG BERT E.

MODDNALD, 0F CHICAGO, ILLINOIS.

ELECTRIC HEATER.

To all whom it may concern.'

Be it known that I, MIN DELIN MGGERRY, a citizen of the United States, residing at Grand Rapids, in the county of Kent and State of Michigan, have invented new and useful Improvements in Electric Heaters, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to provide an im )roved device for heatin air, especially or warming and venti ating apartments into which the air passes from the heater; and itl is also partleularly dcsigned to be used in connection with forced circulation of air for heating or ventilation.

It consists in the elements and features of construction shown and described as indicated in the claims.

In the drawings :-Figurc l is an end eleration of a heater embodying thisinvention. Fig. 2 is a longitudinal section at the line @MQ on Fig. 1.

The heater which constitutes this invention comprises a hollow core, l, open from end to end, about which there is wound the high resistance wire, 5, for generatin heat from a current for electricity of wbici it is a conductor. The coil, :3, wound abouty the hollow core, 1, is separated and insulated therefrom preferably by two layers of mica, 4, 4, which are separated from each other by an asbestos layer, 3. The longitudinal cavity of the hollow core, 1, is designed to constitute a passage for the air to be heated, and for increasing the heat radiating surface of the core there are provided a mnltiplicity of heat-radiating bosses or fingers 1"', relatively broad at the base and taper@ from base to tip projecting from two oppo- .site sides of the interior wall of the core and occupying very largely the cavity of the core but still. leaving a large percentage of air space through the core and about the radiating fingers, la. The core with its heating coil winding, is mounted Within an exterior air conduit, 2, from whose exterior wall it is held spaced by the supportin brackets, 5, 5, the two endsof the` wlre coi 4, running to insulated binding posts, 6 and 7, which pro'ect from the conduit, 2, to receive the in eading 'and outleading Wires respectively of the heating circuit.

The entire device, comprising the outer air conduit and the hollow core forming an injPatented'Mari-1910. serial zip. ligadas, A V

i ,zf '5, Q'gj'l ner air conduitfand havingathe heating coil wound about it.` asf'described,isfdesigned to be connected Withwanymeans-for fm'cingfa L circulation of air through the device, as a fan, not shown, whose discharge mouth will be connected to one end of the other conduit, Q, which is the inlet end of the device shown ixrtlie drawings, the opposite end being connected with an air pipe, 9, for conducting' the heated air current to the apartment; or said end of the device may open directly into the apartment or chamber to be warmed and ventilated. Preferably, the outlet end of the conduit, 2, is reduced in Width or diameter, as shown at 2 the purpose of such reduction beingto cause some compression of the air in the chamber and so retain it somewhat longer in the presence of the heat radiating surfaces.

An important feature of the construction is the exposure of the heating wire coil, 5, bare, to the air current passing over it so that it is adapted to radiate heat more rapidly in proportion as the air current passing over it is more rapid. This makes it possible by running the fan or other device employed to force the air current so as to produce a rapid current of air, to employ without injury to the apparatus an electric current for heating, which in the absence of the `rapid air current would melt the Wire of the coil, and thus makes it possible to use a much smaller device for a given amount of heating than would otherwise be possible.

The fingers, l, are made relatively broad at the base to afford large conductivity from the heated core, l, and tapered from base to tip to obtain area which can be well heated by the conduction ail'orded by extended base and leave adequate air path among the fingers.

1. An electric heater comprising two air conduits, one extending within the other and spaced therefrom; an electric heating coil wound about the inner conduit, insulated therefrom and exteriorly exposed Within the outer conduit, said inner conduit being of metal and havinga multiplicity of inwardly` extending heatradiatin fingers or bosses distributed throughout t e length as well as the breadth of said conduit, obstructing the air path throu h said inner conduit, said fingers being re atively broad at the base and tapered from base to tip.

A11 electric heater com rising two nir thl'ou h said inner conduit, :said fingers bw conduits, one extending within the other and ing re atively broad :it the base :und tapered spaced therefrom; an electric heating coil from base to tip. wound about the inner conduit and insulated In bestimon whereof, I have hereunto set 5 therefrom and exteriorly exposed within the my hand, at xrand Rapids, Mich., thisv 26th 15 outer conduit, said inner conduit having u day of February, 1908.

multiplicity of inWardI-extending heut- MIN DELIN MCGERRY. radiating fingers or osses distributed Witnesses: throu hout the len h as well as the breadth ELIZABETH MGGERRY,

10 of said conduit 0 structing the nir path LEROY G.W1THEY. 

